Seismic Performance Analysis Of R.C Frame Structure With Staggered Floor

With the rapid development of high-rise buildings and people's continuous pursuit of living standards,the complex structures of the staggered floor frame structures are gradually favored by people.The staggered floor frame structures are irregular and have a variety of adverse influencing factors on seismic resistance.The stiffness of the staggered floor is discontinuous.When the earthquake comes,the staggered floor cannot effectively transfer the loads.This unfavorable factor will affect the overall performance of the structure.Short columns or even ultra short columns are easy to be formed at the staggered joints,they are insufficient in ductility and prone to cause stress concentration and shear failure.Therefore,in order to improve the seismic performance of the staggered floor frame structures,appropriate reinforcement measures are particularly important.Firstly,the response spectrum analysis and elastic time-history analysis of the staggered floor frame structure under frequently occurred earthquake action were carried out by using finite element analysis software,and the seismic performance of the structure was analyzed.By using elastic time history analysis,the seismic performance of the structure before and after vertical haunch was compared and analyzed,and the influence of the height and length of haunch on the seismic performance of the structure was discussed.The seismic performance of the structures before and after the reversed beam measure was compared and analyzed,and the influence of the linear stiffness ratio on the seismic performance of the structures was discussed.The results show that both reinforcement measures can effectively improve the seismic performance of the structure.The height of the haunch should be appropriately greater than the net height of the staggered floor.The length of the haunch should be appropriately larger than the plastic hinge length of the beam.The linear stiffness ratio has little effect on the seismic performance of the structure.Secondly,the response spectrum analysis and elastic time-history analysis of the staggered floor frame structure were carried out with different shear span ratio,staggered floor direction and proportion of staggered floor.The results show that the increase of shear span ratio will reduce the seismic performance of the structure,and the influence on the seismic performance is obvious.The change of the staggered floordirection has obvious influence on the seismic performance of the structure.The increase of the proportion of staggered floor members will reduce the seismic performance of the structure,and the influence on the seismic performance of the structure is obvious.Thirdly,the pushover analysis and elasto-plastic time-history analysis of the staggered floor frame structure were carried out under rarely occurred earthquake action.The seismic performance of the structure before and after vertical haunch was compared and analyzed,and the seismic performance of the structures before and after the reversed beam measure was compared and analyzed.The results show that both reinforcement measures can effectively improve the seismic performance of the structure.Finally,the monotonic loading analysis of the staggered joints was carried out.The bearing capacity of the staggered joint before and after vertical haunch was compared,and the influence of loading direction on the bearing capacity of the staggered joints was discussed.The results show that the measure of vertical haunch can effectively improve the bearing capacity of staggered joint.The loading direction has obvious influence on the seismic performance of the staggered joint.